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In this manuscript, a pyridyl containing porphyrin, C46H36N8O4 (denoted as Tris@NTPP) and its derived polyoxometalate-porphyrin hybrid, [C4H9)4N]3[C41H26N7NHCO(NH)C(OCH2)3MnMo6 O18(OCH2)3C(NH)CONHN7 H26C41] (denoted as NTPP@POM) in which two pyridyl containing porphyrin moieties hanged onto one Anderson polyoxometalate, have been successfully synthesized and thoroughly characterized. Fluorescence quenching was observed in NTPP@POM as compared with its precursor Tris@NTPP inferring the transfer of electron/energy from porphyrin moiety to POM moiety. NTPP@POM showed notably enhanced nonlinear absorption (β = 2.32 × 10–5 esu) than Tris@NTPP (β = 0.73 × 10–5 esu). These NLO responses were associated with fluorescence decay mechanism which oriented the singlet excited(*S) states and triplet excited(*T) states of Tris@NTPP and NTPP@POM. Life time decay studies revealed that NTPP@POM (τ2 = 5.32 ns) were stayed for shorter time in excited triplet state than Tris@NTPP (τ2 = 10 ns), implying shorter life time led towards higher NLO responses. [ABSTRACT FROM AUTHOR]

A novel series of polyphosphazene-graft-polystyrene (PP- g-PS) copolymers were successfully prepared by atom transfer radical polymerization (ATRP) of styrene monomers and brominated poly(bis(4-methylphenoxy)phosphazene) macroinitiator. The graft density and the graft length could be regulated by changing the bromination degree of the macroinitiator and the ATRP reaction time, respectively. The PP- g-PS copolymers readily underwent a regioselective sulfonation reaction, which occurred preferentially at the polystyrene sites, producing the sulfonated PP- g-PS copolymers with a range of ion exchange capacities. The resulting sulfonated PP- g-PS membranes prepared by solution casting showed high water uptake, low water swelling and considerable proton conductivity. They also exhibited good oxidative stability and high resistance to methanol crossover. Morphological studies of the membranes by transmission electron microscopy showed clear nanophase-separated structures resulted from hydrophobic polyphosphazene backbone and hydrophilic polystyrene sulfonic acid segments, indicating the formation of proton transferring tunnels. Therefore, these sulfonated copolymers may be candidate materials for proton exchange membranes in direct methanol fuel cell (DMFC) applications. [ABSTRACT FROM AUTHOR]